Memorial Services (Greek: Μνημοσυνα) are special prayer services offered for the benefit of the departed.

Early Christians expressed their concern for the repose of the souls of their beloved by works of charity and love and by personal and communal prayers. The Apostolic Constitutions recommended that part of the possessions of a dead person be distributed to the poor in his "memory". St. John Chrysostom, Jerome, Tertullian, and others also recommended alms giving in memory of the dead although they believe that this and other good works for the repose of the soul of the dead also benefit the doers.

Another kind of memorial was the gathering on the graves of the dead or in the church, and the serving of meals known as "makariai" (meals in memory of) that are still held by many in the church hall following burial.

Praying for the dead could include celebrating the Eucharist or could be a special service, as it is now, in which the names of the dead were mentioned, or it could be both. St. Cyril of Jerusalem mentions the prayers offered for the benefit of all who have died in the faith of Christ, stating that their souls greatly benefit by the prayers of the Church and by offering the Bloodless Sacrifice for the repose of their souls. St. John Chrysostom believes that "to mention the names of the departed in the awesome mystery of the Eucharist results in much benefit for the souls of the beloved." Above all, praying for the dead is a deeply rooted practice in the Church on the belief that the Church of Christ is constituted not only oh her living members but also of her departed ones. The Bloodless Sacrifice of the Orthodox Eucharist, as articulated in all the Liturgies in use, is offered for the benefit of both dead and living faithful. A Biblical basis for praying for the dead may be found in the Epistle of St. James, 5:16, by which the "prayer of a righteous man has great power in its effects."

According to the Apostolic Constitutions, memorial services may be held on the 3rd, 9th, and 40th day, and on the completion of a year from the day of death. These prescribed times are still observed in most Orthodox places. Considering the fact that in the Orthodox Churches of the diaspora a memorial service with the participation of the congregation must be held on a Sunday, the 40th day memorial service is the one universally observed although by necessity, it may not be held exactly on the 40th day. Needless to say, the Orthodox people may give the names of their departed to be mentioned by the priest in the Eucharist at any time.[1]